Re: U1 fried

K5ESS
 

Jerry,

After re-reading your post I now see your point.  But I think it a lot less likely that someone would plug a mono plug into a mono to stereo adapter IMHO.

Mike

K5ESS

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Jerry Gaffke via Groups.Io
Sent: Wednesday, February 28, 2018 11:36 AM
To: BITX20@groups.io
Subject: Re: [BITX20] U1 fried

 

I assume the mono to serial adapter would just short the mono signal to both stereo signals.
So you are back where you started, plugging a mono jack into that adapter will kill the TDA2822M.
Could work if you avoid this, but not foolproof.  And thus not suitable if I'm anywhere in the vicinity.

Might be better to add a series resistor inside the radio, and/or reduce the supply voltage to the TDA2822M

Jerry, KE7ER


On Wed, Feb 28, 2018 at 09:22 am, K5ESS wrote:

It appears at least a few folks have fried U1 by inserting a mono plug in the speaker jack and shorting out the audio.  I’d recommend only wiring up the tip connection and not the ring and then using an external mono to serial adapter for your stereo phones.

 

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